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		<title>three.js webgl - interactive cubes (gpu)</title>
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		<div class="info">
			<a href="http://threejs.org" target="_blank" rel="noopener">three.js</a> webgl - gpu picking
		</div>

		<div id="container"></div>

		<script src="../build/three.js"></script>

		<script src="js/controls/TrackballControls.js"></script>
		<script src="js/utils/BufferGeometryUtils.js"></script>
		<script src="js/libs/stats.min.js"></script>

		<script>

			var container, stats;
			var camera, controls, scene, renderer;
			var pickingData = [], pickingTexture, pickingScene;
			var highlightBox;

			var mouse = new THREE.Vector2();
			var offset = new THREE.Vector3( 10, 10, 10 );

			init();
			animate();

			function init() {

				container = document.getElementById( "container" );

				camera = new THREE.PerspectiveCamera( 70, window.innerWidth / window.innerHeight, 1, 10000 );
				camera.position.z = 1000;

				controls = new THREE.TrackballControls( camera );
				controls.rotateSpeed = 1.0;
				controls.zoomSpeed = 1.2;
				controls.panSpeed = 0.8;
				controls.noZoom = false;
				controls.noPan = false;
				controls.staticMoving = true;
				controls.dynamicDampingFactor = 0.3;

				scene = new THREE.Scene();
				scene.background = new THREE.Color( 0xffffff );

				pickingScene = new THREE.Scene();
				pickingTexture = new THREE.WebGLRenderTarget( 1, 1 );

				scene.add( new THREE.AmbientLight( 0x555555 ) );

				var light = new THREE.SpotLight( 0xffffff, 1.5 );
				light.position.set( 0, 500, 2000 );
				scene.add( light );

				var pickingMaterial = new THREE.MeshBasicMaterial( { vertexColors: THREE.VertexColors } );
				var defaultMaterial = new THREE.MeshPhongMaterial( { color: 0xffffff, flatShading: true, vertexColors: THREE.VertexColors, shininess: 0	} );

				function applyVertexColors( geometry, color ) {

					var position = geometry.attributes.position;
					var colors = [];

					for ( var i = 0; i < position.count; i ++ ) {

						colors.push( color.r, color.g, color.b );

					}

					geometry.addAttribute( 'color', new THREE.Float32BufferAttribute( colors, 3 ) );

				}

				var geometriesDrawn = [];
				var geometriesPicking = [];

				var matrix = new THREE.Matrix4();
				var quaternion = new THREE.Quaternion();
				var color = new THREE.Color();

				for ( var i = 0; i < 5000; i ++ ) {

					var geometry = new THREE.BoxBufferGeometry();

					var position = new THREE.Vector3();
					position.x = Math.random() * 10000 - 5000;
					position.y = Math.random() * 6000 - 3000;
					position.z = Math.random() * 8000 - 4000;

					var rotation = new THREE.Euler();
					rotation.x = Math.random() * 2 * Math.PI;
					rotation.y = Math.random() * 2 * Math.PI;
					rotation.z = Math.random() * 2 * Math.PI;

					var scale = new THREE.Vector3();
					scale.x = Math.random() * 200 + 100;
					scale.y = Math.random() * 200 + 100;
					scale.z = Math.random() * 200 + 100;

					quaternion.setFromEuler( rotation, false );
					matrix.compose( position, quaternion, scale );

					geometry.applyMatrix( matrix );

					// give the geometry's vertices a random color, to be displayed

					applyVertexColors( geometry, color.setHex( Math.random() * 0xffffff ) );

					geometriesDrawn.push( geometry );

					geometry = geometry.clone();

					// give the geometry's vertices a color corresponding to the "id"

					applyVertexColors( geometry, color.setHex( i ) );

					geometriesPicking.push( geometry );

					pickingData[ i ] = {

						position: position,
						rotation: rotation,
						scale: scale

					};

				}

				var objects = new THREE.Mesh( THREE.BufferGeometryUtils.mergeBufferGeometries( geometriesDrawn ), defaultMaterial );
				scene.add( objects );

				pickingScene.add( new THREE.Mesh( THREE.BufferGeometryUtils.mergeBufferGeometries( geometriesPicking ), pickingMaterial ) );

				highlightBox = new THREE.Mesh(
					new THREE.BoxBufferGeometry(),
					new THREE.MeshLambertMaterial( { color: 0xffff00 }
					) );
				scene.add( highlightBox );

				renderer = new THREE.WebGLRenderer( { antialias: true } );
				renderer.setPixelRatio( window.devicePixelRatio );
				renderer.setSize( window.innerWidth, window.innerHeight );
				container.appendChild( renderer.domElement );

				stats = new Stats();
				container.appendChild( stats.dom );

				renderer.domElement.addEventListener( 'mousemove', onMouseMove );

			}

			//

			function onMouseMove( e ) {

				mouse.x = e.clientX;
				mouse.y = e.clientY;

			}

			function animate() {

				requestAnimationFrame( animate );

				render();
				stats.update();

			}

			function pick() {

				//render the picking scene off-screen

				// set the view offset to represent just a single pixel under the mouse

				camera.setViewOffset( renderer.domElement.width, renderer.domElement.height, mouse.x * window.devicePixelRatio | 0, mouse.y * window.devicePixelRatio | 0, 1, 1 );

				// render the scene

				renderer.render( pickingScene, camera, pickingTexture );

				// clear the view offset so rendering returns to normal

				camera.clearViewOffset();

				//create buffer for reading single pixel

				var pixelBuffer = new Uint8Array( 4 );

				//read the pixel

				renderer.readRenderTargetPixels( pickingTexture, 0, 0, 1, 1, pixelBuffer );

				//interpret the pixel as an ID

				var id = ( pixelBuffer[ 0 ] << 16 ) | ( pixelBuffer[ 1 ] << 8 ) | ( pixelBuffer[ 2 ] );
				var data = pickingData[ id ];

				if ( data ) {

					//move our highlightBox so that it surrounds the picked object

					if ( data.position && data.rotation && data.scale ) {

						highlightBox.position.copy( data.position );
						highlightBox.rotation.copy( data.rotation );
						highlightBox.scale.copy( data.scale ).add( offset );
						highlightBox.visible = true;

					}

				} else {

					highlightBox.visible = false;

				}

			}

			function render() {

				controls.update();

				pick();

				renderer.render( scene, camera );

			}

		</script>

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